Handling device with a reversible toroidal gripping member

ABSTRACT

A handling device includes a gripping member ( 2 ) and a support structure ( 16 ) that supports the gripping member. The gripping member ( 2 ) includes a flexible, substantially toroidal wall member ( 10 ) having an outer wall portion ( 10   b ) and an inner wall portion ( 10   a ) that defines an axial passageway ( 12 ) through the grip-ping member. A fluid fills the volume enclosed by the wall member The support structure ( 16 ) includes a drive mechanism ( 18, 20 ) that engages the wall member ( 10 ) and is constructed and arranged to provide relative axial movement between the inner and outer wall portions ( 10   a,    10   b ).

[0001] The present invention relates to a handling device and inparticular, but not exclusively, to a handling device for goods that aregenerally considered difficult to handle, for example goods that aresoft, delicate, irregular in size and shape or sticky, or a combinationof these and other properties.

[0002] Many handling devices are available, most of these being modelledon the gripping action of the human hand. However, few of these aresuitable for handling goods of the types mentioned above, and such goodsoften therefore are handled by hand. However, this impedes automationand in certain circumstances leads to additional problems, such ascontamination of the goods and exposure of personnel to hazardous orunpleasant materials. There is a need therefore for a handling devicethat is suitable for handling such goods.

[0003] More specifically, in agriculture, there is a need for a devicethat is capable of harvesting soft fruits without damaging them, and forsorting and grading goods of irregular size and shape, such asvegetables.

[0004] In the food industry, there is a problem with handling goods thatare soft and easily damaged, or irregular in shape (for example, bakerygoods). In addition, there is a need for a device that can handleflowable goods such as uncooked dough, sticky goods, hot goods (forexample goods in an oven), or frozen goods. Furthermore, where there isa risk of cross-contamination, it is important that the food contactingpart of the device should be easily cleaned or disposable.

[0005] In other situations, it may be necessary to handle hazardousgoods such as nuclear waste, or goods that are contaminated withdangerous chemical or biological waste, or objects that are simplyunpleasant to handle, such as insects, laboratory animals, or dogfaeces.

[0006] Finally, there is a need for a general purpose handling devicefor use by people with an impaired handling ability, such as people witha disability or who suffer from Parkinson's disease.

[0007] It is an object of the present invention to provide a handlingdevice that mitigates at least some of the aforesaid problems.

[0008] According to the present invention there is provided a handlingdevice including a gripping member and a support structure that supportsthe gripping member, wherein the gripping member includes a flexible,substantially toroidal wall member having an outer wall portion and aninner wall portion defining an axial passageway that extends through thegripping member, and a fluid that fills the volume enclosed by the wallmember, wherein the support structure includes a drive mechanism thatengages the wall member and is constructed and arranged to providerelative axial movement between the inner and outer wall portions.

[0009] Providing relative axial movement between the inner and outerwall portions causes the toroidal wall member to rotate through theaxial passageway and around the exterior of the gripping member. Anobject placed at the entrance of the passageway will be enveloped by thegripping member and drawn into the passageway. However, because the wallmember is flexible, it will conform to the object, thereby gripping itwithout causing damage. Conversely, by rotating the wall member in theopposite direction, the object will be rejected from the passageway andreleased from the gripping device. The rolling action of the wall memberas it releases the object is ideal for releasing sticky objects, whichpeel off the gripping member without adhering to it.

[0010] The device is suitable for handling objects of different sizesand shapes, since the gripping member conforms to the object. It alsohas a self-centring action, drawing objects inwards towards the axialpassageway, even if they are not located precisely on the axis of thedevice.

[0011] A further advantage of the handling device is that it is capableof gripping an object without having to reach behind the object. It istherefore ideal for gripping objects where only the front face of theobject is accessible, such as a foreign object that is stuck inside apatient's nose or ear.

[0012] The wall member may be made of an elastomeric material, forexample natural or synthetic rubber. This provides a highly flexiblesurface that conforms well to the object being picked up and also rollswell when the drive mechanism is activated.

[0013] The fluid that fills the gripping member may be a liquid or agas. Advantageously, the pressure of the fluid in the gripping member issubstantially equal to atmospheric pressure (or ambient pressure, ifthis is not the normal atmospheric pressure). The gripping member thenexerts very little pressure on the object being lifted, so minimisingthe risk of causing damage. The handling device may include means foradjusting the pressure of the fluid in the gripping member.

[0014] Preferably, the gripping member contains a lubricant to reducefriction between the sections of the wall member as they roll around theend of the toroid.

[0015] The handling device preferably includes an inner drive mechanismthat engages the inner wall portion and is constructed and arranged toprovide relative axial movement between the inner wall portion and thesupport structure, and an outer drive mechanism that engages the outerwall portion and is constructed and arranged to provide relative axialmovement between the outer wall portion and the support structure. Bydriving both the inner and the outer wall portions, a full range ofmovement of the gripping member can be provided.

[0016] The inner and outer drive mechanisms may be interlinked foropposed movement, or the inner and outer drive mechanisms may be capableof independent movement. This latter arrangement permits axial movementof the gripping member relative to the support structure.

[0017] Advantageously, the drive mechanism engages a first one of saidinner and outer wall portions and the support structure engages a secondone of said inner and outer, wall portions, the drive mechanism beingconstructed and arranged to provide relative axial movement between thefirst wall portion and the support structure. This provides aparticularly simple drive mechanism. The drive mechanism may beconstructed such that it engages the inner wall portion and the supportstructure engages the outer wall portion, or alternatively such that itengages the outer wall portion and the support structure engages theinner wall portion.

[0018] The drive mechanism may include one or more drive belts thatengage the wall member. This provides an effective method of driving theflexible wall member and allows for continuous rotation of the wallmember in either direction. Preferably, the handling device includes aplurality of radially-spaced drive mechanisms.

[0019] The axial length of the toroidal wall member may be greater thanits diameter, and is preferably at least twice its diameter, providing,an, elongate toroid. The axial passageway through the gripping memberwill also then be elongate, allowing it to accommodate and grip mostobjects securely.

[0020] The handling device may include a sensor for sensing the presenceof an object in the passageway. This may be linked to a control device,which stops the drive mechanism as soon as an object is detected in thepassageway. The sensor preferably senses light reflected from an objectin the passageway.

[0021] The handling device may include a sensor for sensing the positionof the gripping member relative to the support structure. This may alsobe linked to a control device, which controls the position of thegripping member relative to the support structure.

[0022] Various embodiments ofthe present invention will now bedescribed, byway of example, with reference to the accompanyingdrawings, in which:

[0023]FIGS. 1a, 1 b and 1 c illustrate a method of constructing aflexible gripping member, forming part of a handling device according toan embodiment of the invention;

[0024]FIG. 2 is a side section of a first handling device;

[0025]FIGS. 3a to 3 d are side sections, illustrating the principles ofoperation ofthe handling device shown in FIG. 2;

[0026]FIGS. 4a to 4 g are side sections, illustrating a typical sequenceof operations using the handling device shown in FIG. 2;

[0027]FIG. 5 is a further side section of the handling device shown inFIG. 2;

[0028]FIG. 6 is an isometric view of the support structure of a handlingdevice,

[0029]FIG. 7 is an end view of the support structure;

[0030]FIG. 8 is a side section of the support structure;

[0031]FIG. 9 is a side section of a hand-held handling device;

[0032] FIGS. 10 to 14 illustrate various possible applications of ahandling device according to the invention;

[0033]FIGS. 15a and 15 b are side sections of further hand-held handlingdevices, and

[0034]FIG. 16 illustrates use of a handling device as shown in FIG. 1a.

[0035] A method of constructing a flexible gripping member 2 that formspart of a handling device according to the invention is illustrated inFIGS. 1a, 1 band 1 c. As shown in FIG. 1a, the gripping member 2 isconstructed from a rectangular sheet 4 of an elastomeric material, forexample natural or synthetic rubber, having two long side edges 6 andtwo shorter end edges 8. The two side edges 6 are brought together asshown in FIG. 1band joined, for example using an adhesive, forming acylindrical tube. Alternatively, a preformed tube may be used. The endedges 8 are then brought together and joined, forming a gripping member2, as shown in FIG. 1c, that has a continuous toroidal wall 10comprising an inner wall portion 10 a and an outer wall portion 10 b.

[0036] A passageway 12 defined by the inner wall portion 10 a extendsaxially through the gripping member 2. The wall 10 can rotate, the innerportion 10 a passing through the passageway 12 in one direction whilethe outer portion 10 b travels in the opposite direction around theoutside of the gripping member 2. It will be understood that the entirewall 10 can rotate through the passageway 12 and that the terms “innerwall portion” and “outer wall portion” refer to the portions of the wallthat form the inner and outer surfaces of the toroidal gripping member 2at that time.

[0037] The volume enclosed by the toroidal wall 10 of the grippingmember 2 is filled with a fluid, for example a liquid such as purifiedwater, or a gas such as air. The fluid is at a low pressure, whichallows the gripping member 2 to deform easily. The enclosed volume mayalso include a lubricant, for example an oil or a fine powder such astalc, which allows the inner and outer portions 10 a, 10 b of the wall10 to pass over each other with very little friction.

[0038] A handling device 14 that includes a flexible gripping member 2is shown in cross-section in FIG. 2. The gripping member 2 is supportedby a support structure 16 that includes an inner drive mechanism 18 andan outer drive mechanism 20.

[0039] The inner drive mechanism 18 is located within the axialpassageway 12 in the gripping member 2 and includes a set of drive belts22, each of which is mounted on a pair of pulley wheels 24, 26. Theinner pulley wheel 24 is driven by a drive motor (not shown). The drivebelt 22 has a toothed inner surface that engages corresponding toothformations (not shown) on the pulley wheels 24, 26 and a flat outersurface that engages the inner portion 10 a of the toroidal wall. Theouter surface of the belt 22 may be roughened, for example by means ofan abrasive material adhered to that surface, to provide a highcoefficient of friction between the belt and the inner portion 10 a ofthe toroid wall. The number of drive belts 22 provided in the innerdrive mechanism may vary from two to eight or more, but will usually befour.

[0040] The outer drive mechanism 20 engages the outer portion 10 b ofthe toroidal wall and is similar to the inner drive mechanism, includinga set of drive belts 28, each of which is mounted on a pair of pulleywheels 30, 32. The inner pulley wheel 30 is driven by a drive motor (notshown).

[0041] The inner drive mechanism 18 and the outer drive mechanism 20 canbe driven independently, allowing the handling device 14 to be operatedaccording to the principles of operation illustrated in FIGS. 3a to 3 d.For simplicity, only one inner drive mechanism 18 and one outer drivemechanism 20 is shown in each of these drawings.

[0042] In FIG. 3a, the inner drive mechanism 18 and the outer drivemechanism 20 are both stationary. The gripping member 2 is alsotherefore stationary. In FIG. 3b, the inner drive mechanism 18 isrotating anti-clockwise and the outer drive mechanism 20 is rotatingclockwise. The inner and outer walls 10 a, 10 b of the gripping member 2are both being driven in the same direction, with the result that thegripping member 2 is being extended from the support structure 16. Thedrive directions of the drive mechanisms are reversed in FIG. 3c, withthe result that the gripping member 2 is being retracted towards thesupport structure 16. In FIG. 3d, the inner drive mechanism 18 and theouter drive mechanism 20 are both being driven anti-clockwise. The innerwall 10 a of the gripping member 2 is therefore being driven away fromthe support structure 16, while the outer wall 10 b is being driventowards it. As a result, the wall 10 is rotating around the grippingmember while the gripping member remains in the same place.

[0043]FIGS. 4a to 4 g illustrate schematically a typical sequence ofhandling operations, using the handling device shown in FIG. 2, to pickup and place an object. In this example, the object 34 represents afruit such as an cherry that is attached to a stalk 36. The handlingdevice 14 is presumed to be attached to a support structure (not shown),for example a robotic arm.

[0044] The handling device 14 is positioned so that the object 34 isclose to the free end of the gripping member 2 and approximately in linewith the passageway 12 (FIG. 4a). The gripping member is extendedtowards the object 34 by rotating the inner and outer drives in oppositedirections (FIG. 4b), such that the inner and outer wall portions areboth driven towards the object. When the end of the gripping membertouches the object, the inner drive 18 stops but the outer drive 20continues to rotate, so that the gripping member 2 surrounds and gripsthe object (FIG. 4c). Both drives are then activated to withdraw theinner and outer wall portions, thereby retracting the gripping member 2and picking the object 34 from the stalk 36 (FIG. 4d).

[0045] The handling device 14 is relocated to the position where theobject is to be placed, and the inner drive 18 is then activated,driving the inner wall 10 a and the object 34 outwards (FIG. 4e). Theinner drive then stops and the outer drive 20 is activated, releasingthe object (FIG. 4f). Finally, both drives rotate in the same direction,causing the wall 10 of the gripping member to rotate (FIG. 4g). Thisproduces a cleaning action, preventing cross-contamination of productspicked up by the device.

[0046]FIG. 5 is a further cross-sectional view of the handling device onan enlarged scale, showing that it can accommodate more than one object34 of a suitable size in the passageway 12. This provides an advantagein terms of work rate, in that the device does not have to be relocatedto the set-down position every time an object has been picked up.

[0047] The support structure 16 of a handling device is shown in detailin FIGS. 6 to 8. For clarity, the gripping member 2 has been omitted.

[0048] The support structure 16 includes a base member 40 that serves,in use, to attach the device to, for example, a robot arm, and supportsthe inner and outer drive mechanisms 18, 20. The outer drive mechanism20 includes four outer support arms 42 that support the outer drivebelts 28 on near and far end pulleys 30, 32. The belts and the pulleysare toothed. The near end pulleys 30 are interconnected for synchronousmovement by means of shafts 44 and bevel gears 46, and are driven from adrive shaft 48.

[0049] The inner drive mechanism 18 also includes four inner supportarms 52 that support the inner drive belts 22 on near and far endpulleys 24, 26. Those belts and the pulleys are also toothed. The nearend pulleys 24 are interconnected for synchronous movement by means ofshafts 54 and left- and right-handed pairs of helical gears 56, and aredriven from an inner drive shaft 58.

[0050] As shown in FIG. 7, the gripping member 2 is located between thefour outer drive belts 28, which engage the outer wall portion 10 b ofthe gripping member. The inner drive belts 22 engage the inner wallportion 10 a of the gripping member.

[0051] At the centre of the base structure 40, between the four innersupport arms 52, an object sensor 60 is provided. The object sensor 60includes a light source and a light detector that are mounted remotelyand connected to the sensing position through optical fibres. In use,the sensor detects light reflected from an object in the axialpassageway 12 through the gripping member. Therefore, when an object ispicked up by the handling device, the sensor 60 can detect its presence.Additional sensors (not shown) may be provided if required, for sensingthe position ofthe gripping member 2 relative to the support structure16. The output of those sensors may be used to control operation of thedevice and ensure that the gripping member is maintained in a goodoperating position and is not accidentally lost through being extendedtoo far beyond the support structure.

[0052] A further embodiment of the handling device is shown in FIG. 9.This version is intended for hand-held use, either by people who havedifficulty handling small objects or maintaining a film hold (forexample, people with disabilities or who suffer from a disease thatimpairs dexterity, such as Parkinson's disease), or for handling objectswhen touching with the hand is undesirable. This latter category ofarticles includes articles that are unpleasant or dangerous to touch,that are very fragile or delicate, or where contamination is to beavoided. Some examples include articles contaminated with dangerouschemical, radioactive and biological substances, excreta or otherunpleasant substances, live spiders or laboratory animals, forensicevidence or human tissue during surgical procedures.

[0053] The handling device includes a toroidal gripping member 2 that issubstantially as described above, and a hand-held support structure 70.The support structure 70 includes inner and outer drive mechanisms 72,74 each of which includes a support arm 76, 78 that is mounted forsliding movement in a housing 80. At its free end, the inner support arm76 includes a cylindrical member 82 that is either attached, for exampleby means of adhesive, to the inner wall portion 10 a of the grippingmember 2, or is simply gripped by the gripping member. The free end ofthe outer support arm 78 is attached to the outer wall portion 10 b ofthe gripping member 2 through an attachment means 84 in the form ofarcuate cross-member. Alternatively, the attachment means 84 may consistof a rigid circular band that encircles the gripping member 2.

[0054] Each support arm includes at its inner end a rack 86, 88 that isengaged by an outer gear 90 on a pinion 92 that is mounted in thehousing 80. A second smaller gear 94 that forms part of the same pinion92 and rotates with the first gear 90 is engaged by a drive-rack 96 thatpasses through a slide bracket 98 on which the axle 100 of the pinion ismounted. The drive rack 96 is attached to a sliding plunger 102 that isintended for manual operation and is biassed outwards by a compressionspring 104 located between the plunger and the housing 80.

[0055] In use, pressing the plunger 102 inwards towards the housing 80causes the pinion 92 to rotate anti-clockwise. This drives the outersupport arm 78 outwards while drawing the inner support arm 76 inwards,with the result that the peripheral wall 10 of the gripping member 2rotates so as to draw an object at the free end of the gripping memberinto the passageway 12. Releasing the plunger 102 causes the pinion 92to rotate anti-clockwise, releasing the object from the passageway 12.The device may thus be used to pick up and release objects, simply bypressing and releasing the plunger 102.

[0056] The device shown in FIG. 9 may be modified to meet the needs ofthe user. For example, the drive rack 96 may be relocated onto theopposite side of the pinion 92, to reverse the action of the device, sothat pulling the plunger 102 draws an object into the passageway. Theplunger may also be oriented in different directions and, if used forexample as a prosthetic device, it may be activated by a cable attachedto the plunger 102 and the waist band of the user, causing the device togrip as the user extends his or her arm.

[0057] Various different applications of handling devices as describedare illustrated in FIGS. 10 to 14. FIG. 10 illustrates a robotic pickand place device 110 including a robot arm 112 having at one end ahandling device 114 according to the present invention. The device isused to pick up and place fragile or delicate items, for example softfruit 116, travelling on a conveyor belt 118.

[0058]FIG. 11 shows a fruit harvesting machine 120 that includes awheeled base 122, a robotic arm 112 and a handling device 114. Themachine may be used for example for harvesting soft fruit, such ascherries, from a tree 124.

[0059]FIG. 12 illustrates the use of a plurality of handling devices 114mounted on a common base structure 126 for handling a plurality ofarticles 116 simultaneously, for example on a conveyor belt 118.

[0060]FIG. 13 illustrates the concept of a prosthetic attachment 128that resembles a human hand and includes a handling device 114 accordingto the invention.

[0061]FIG. 14 illustrates a hand-held handling device 130 that includesa handling device 114 according to the invention, for use as arehabilitation aid, for example by Parkinson's sufferers.

[0062] Two further hand-held handling devices 140 are shown in FIGS.15a, 15 b and 16, the version shown in FIG. 15b being a modification ofthe version shown in FIG. 15a.

[0063] The version shown in FIG. 15a includes a tubular substantiallycylindrical support structure 142 that is closed at one end by acircular plate 144 and is open at the other end 146. Outwardly extendingflanges 145 forming finger grips are provided at the closed end of thesupport structure and a narrow flange 148 that extends inwards isprovided at the open end of the support structure 142. The toroidalgripping member 2 is located within the tubular support structure 142and extends a short distance beyond its open end 146.

[0064] A manual drive mechanism 150 is provided, comprising an actuatingbutton 152 that is connected by a shaft 154 to a spherical drive member156. The shaft 154 extends through a bore 158 in the end plate 144, andthe drive member 156 is gripped within the axial passageway 12 of thegripping member 2. The entire drive mechanism 150 is biassed outwards bya compression spring 160 located between the end plate 144 and theactuating button 152. The gripping member 2 is retained in positionwithin the support structure 142 by gripping action of the grippingmember on the drive member 156 and the flange 148. The entire drivemechanism 150 is biassed outwards by a compression spring 160 locatedbetween the end plate 144 and the actuating button 152.

[0065] To actuate the device, the actuating button 150 is pressedtowards the support structure 142, driving the inner wall portion 10 aof the gripping member 2 outwards relative to the outer wall portion 10b . The device is then placed against the object that is to be picked upand the button 152 is released, drawing the object into the passageway12. The button 152 is pressed again to release the object. FIG. 16 showshow the device 140 is held for use in the user's hand 161.

[0066] The device shown in FIG. 15b is similar in most respects to thatshown in FIG. 15a, the only significant difference being that the drivemechanism 150 has a cross-member 162 that is connected to the shaft 154and extends outwards through slots 164 in the side wall of the tubularsupport structure 142, the outwardly-extending ends of the cross-member162 being connected to finger grips 166. The spring 160 is capturedbetween the cross-member 162 and the end plate 144.

[0067] Operation is reversed as compared to the device shown in FIG.15a, in that the end plate 144 is pressed towards the finger grips 166to grip an object and is released to release the object. Variousmodifications of the handling device are of course possible, someexamples of which will now be described. The size of the device may beadapted according to its intended application, with the diameter of thegripping member varying from a few millimetres to a metre or more.

[0068] The pressure of the fluid (the gas or liquid) in the grippingmember may be adjustable, to control how firmly the device grips anobject. The device may include means for adjusting the pressureautomatically during operation. This may be achieved, for example, bymounting one of the support arms 42 on a pivot and adjusting theposition of that arm so that it presses harder or less hard against thewall 10 of the toroidal gripping member 2.

[0069] The device may include a mechanism for cleaning the grippingmember during use, for example by rotating the gripping member against acleaning surface or past a washing station. Alternatively, or inaddition, the gripping member may be disposable or removable forcleaning.

1. A handling device including a gripping member and a support structurethat supports the gripping member, wherein the gripping member includesa flexible, substantially toroidal wall member having an outer wallportion and an inner wall portion defining an axial passageway thatextends through the gripping member, and a fluid that fills the volumeenclosed by the wall member, and the support structure includes a drivemechanism that engages the wall member and is constructed and arrangedto provide relative axial movement between the inner and outer wallportions.
 2. A handling device according to claim 1, wherein the wallmember is made of an elastomeric material.
 3. A handling deviceaccording to claim 2, wherein the wall member is made of natural orsynthetic rubber.
 4. A handling device according to any one of thepreceding claims, wherein the gripping member is filled with a liquid.5. A handling device according to any one of the preceding claims,wherein the gripping member is filled with a gas
 6. A handling deviceaccording to any one of the preceding claims, wherein the pressure ofthe fluid in the gripping member is substantially equal to atmosphericpressure.
 7. A handling device according to any one of the precedingclaims, including means for adjusting the pressure of the fluid in thegripping member.
 8. A handling device according to any one of thepreceding claims, wherein the gripping member contains a lubricant.
 9. Ahandling device according to any one of the preceding claims, includingan inner drive mechanism that engages the inner wall portion and isconstructed and arranged to provide relative axial movement between theinner wall portion and the support structure, and an outer drivemechanism that engages the outer wall portion and is constructed andarranged to provide relative axial movement between the outer wallportion and the support structure.
 10. A handling device according toclaim 9, in which the inner and outer drive mechanisms are interlinkedfor opposed movement.
 11. A handling device according to claim 9, inwhich the inner and outer drive mechanisms are capable of independentmovement.
 12. A handling device according to any one of the precedingclaims, wherein the drive mechanism that engages a first one of saidinner and outer wall portions, the support structure engages a secondone of said inner and outer wall portions, the drive mechanism beingconstructed and arranged to provide relative axial movement between thefirst wall portion and the support structure.
 13. A handling deviceaccording to any one of the preceding claims, in which the drivemechanism includes a chive belt that engages the wall member.
 14. Ahandling device according to any one of the preceding claims, includinga plurality of radially-spaced drive mechanisms.
 15. A handling deviceaccording to any one of the preceding claims, in which the axial lengthof the toroidal wall member is greater than its diameter, and ispreferably at least twice its diameter.
 16. A handling device accordingto any one of the preceding claims, including a sensor for sensing thepresence of an object in the passageway.
 17. A handling device accordingto claim 16, in which the sensor senses light reflected from an objectin the passageway.
 18. A handling device according to any one ofthepreceding claims, including a sensor for sensing the position of thegripping member relative to the support structure.